Study On Depositional Background (Earlier Late Carboniferous) In Xinjiang Area, Jiangxi Province

Yongping copper mine located in the east of Jiangxi Province, which is not only a large copper and sulfur polymetallic ore, but also an important base of copper and sulfur mine production in china. But its'mining resources has become less and less because of the40years of continuously mineral exploitation, so it's very necessary and urgent to get a further study about the cause of ore deposit. Across the sedimentary background study of Yongping copper mine, this paper mainly providing a new evidence to clarify the formation cause of the ore deposit, and then providing the basis supporting for the reconnaissance of new resources.This article is mainly researching the characteristics of the geochemistry, sediment and sedimentary facies, synsedimentary fault and correlative sediments of Outangdi Formation and Huanglong Formation from Xinjiang region. And it can also get a discussion by combining the early Late Carboniferous sedimentary background with the conditions for the formation causes of Yongping copper mine. The main achievements are as follows:1) The cherts in the strata of early Late Carboniferous from Xinjiang region, are formed from the continental margin and mainly formed by the hydrotherm sediments. The stratigraphic position and space distribution of the unusual Eu-silicolites in the research region indicated that many times of marine hydrothermal activities exist in this period, and the Yongping-Tiancaoping region is the high strength area of submarine hydrothermal activities.2) Huanglong Formation mainly exposed in Yangtze stratigraphic region which north the Pingxiang-Guangfeng deep fault. It is chiefly composed of carbonate and contains Profusulinella. Meanwhile, Outangdi Formation is composed of siliceous clastic rock, pelite and carbonate. It is major exposed in Cathaysian stratigraphic region and at the other side of the deep fault. In middle Outangdi Formation it contains fusulinids fossil such as Pseudostaffella, Profusulinella, Fusulinella, Fusulina, etc.3) The research of synsedimentary fault and correlative sediments confirms that there are stretch, high-angle normal faults and SWW-NEE trend synsedimentary faults growing in the middle Outangdi Formation and bottom Huanglong Formation, in early Late Carboniferous. The synsedimentary faults distribute near the Pingxiang-Guangfeng Deep Riftzone, and often have a large scale and strong activity on the south of it.4) In the deposited period of L-middle Outangdi Formation, Yongping area was located in the centre of Xinjiang sedimentary basin, along with a high hydrothermal activity and the most deep sedimentary environment. In the meantime, it was also in such a background that pull-geotectonic and intensive synsedimentary fault activities. This paper stand for the submarine hydrothermal jet minerallization with the appropriate geology background which have mentionedThis paper provide new data for a deep understanding to the early Late Carboniferous cherts in Xinjiang region, for its'geochemical, sedimentary, palaeogeographic and the paleostructure characteristics. It can not only provide new materials to clarify the formation cause of Yongping copper mine, but also offer new evidences for the viewpoint that submarine hydrothermal jet-flow deposition formed the Yongping copper mine. Then they could be a great help to the reconnaissance of the new resources.